HC-12 wireless serial port communication module is a new-generation multichannel embedded wireless data transmission module. Its wireless working frequency band is 433.4-473.0MHz, multiple channels can be set, with the stepping of 400 KHz, and there are totally 100 channels. The maximum transmitting power of module is 100mW (20dBm), the receiving sensitivity is -117dBm at baud rate of 5,000bps in the air, and the communication distance is 1,000m in open space. There is MCU inside the module, and user don’t need to program the module separately, and all transparent transmission mode is only responsible for receiving and sending serial port data, so it is convenient to use. The module adopts multiple serial port transparent transmission modes, and user could select them by AT command according to use requirements. The average working current of three modes FU1, FU2 and FU3 in idle state is 80μa, 3.6mA an 16mA respectively, and the maximum working current is 100mA (in transmitting state).     This module can not work individually, at least 2 pcs would be needed to create the communication. Please also note that this module do not work with the 434Mhz Serial RF Module HC-11.      Please solder the Antenna as below: